Nuclear power: All that you need to know about small modular reactors

Small modular reactors are advanced reactors that have a power generation capacity of up to 300 megawatts (MW) per unit

India is taking steps to develop small modular nuclear reactors (SMRs), Union minister Jitendra Singh said at an event on Sunday. 

At a workshop on Small Modular Reactors (SMR) organised by NITI Aayog and the Department of Atomic Energy, he said the participation of the private sector and start-ups needs to be explored in the development of this critical technology within India.

This will also help the country in boosting its efforts to reduce greenhouse gas (GHG) emissions, he said.

But what are small modular reactors (SMRs)?

Small modular reactors are advanced nuclear reactors that have a power generation capacity of up to 300 megawatts (MW) per unit. This is one-third the capacity of a traditional nuclear reactor. However, the main benefit of the SMR is that it is small and modular.

SMRs were designed to do away with the problems in conventional nuclear plants. Conventional nuclear reactors are massive in size and have a high cost of construction. According to some estimates, the construction of these plants may cost up to $5,945 per kilowatt capacity. SMRs provide a solution to all this. 

What are the advantages of SMRs?

The small size of these reactors makes it possible for the companies to install them on difficult terrain. Their modular property allows the company to transport them easily from the manufacturing location to the plant. It brings down their cost of production as well as the construction time.

In areas which lack sufficient grid capacity, like rural regions, SMRs can be installed into the existing grid and increase the power output. The SMRs provide low-carbon power, which is less harmful to the environment as compared to thermal power.

According to the International Atomic Energy Agency (IAEA), SMRs are relatively safer. No human intervention or external power or force is required to shut down systems because passive systems rely on physical phenomena like gravity and self-pressurisation.

"These increased safety margins, in some cases, eliminate or significantly lower the potential for unsafe releases of radioactivity to the environment and the public in case of an accident," it added.

Moreover, these reactors require less frequent refuelling. As compared to refuelling once every 1-2 years in conventional plants, these plants can last 3-7 years before refuelling.

"Some SMRs are designed to operate for up to 30 years without refuelling," IAEA added.

How many SMRs are currently operating?

Over 70 commercial SMRs have been developed around the world, but the only modular reactor design that is operating is onboard the floating nuclear power plant Akademik Lomonosov in Russia.

The construction of the biggest land-based SMR began in the Chinese power plant Linglong One in 2021 and is due for completion in 2026.

What are the disadvantages of SMRs?

The SMRs are largely more beneficial than conventional nuclear plants and other forms of power generation, but their cost of production is likely to stay high unless mass production is undertaken.

In a 2021 interview Anil Kakodkar, former chairman of the Atomic Energy Commission of India, said, "At the moment their specific capital cost would be higher as compared to large plants unless the benefit of mass production can be leveraged. That is a matter of market development requiring a massive policy push."

Now, with the Centre's involvement, SMRs may become more viable.